2.0 Analysis 2.1 The Transfer Operation The pilot boat came alongside the bulk carrier without making arrangements with the pilot who had the conduct of the vessel. Unlike the master of the pilot boat, the pilot on board the large vessel has a better perspective and is therefore in a better position to decide when the transfer should be made. The pilot can take the surrounding traffic into account when controlling the vessel's speed and heading. The master of the pilot boat is not in such a position. The pilot transfer was made at an approximate speed of 9.9 knots through the water, which was greater than usual. There is no regulatory speed range for approach manoeuvres and pilot transfers. Because there are no standards for these operations, the pilots and the crews on the pilot boats must use good seamanship principles and bear in mind the particular operational characteristics of the pilot boat. 2.2 Choice of Ladder for the Transfer MCTS traffic regulating officers instruct the crews of foreign vessels to use the accommodation ladder, but this is not in accordance with international and Canadian regulations. The custom on the St. Lawrence River for a number of decades has been for pilots to use the accommodation ladder rather than the pilot ladder, unless exceptional conditions require a departure from that practice. Although it is easier to climb up an accommodation ladder than a pilot ladder, the former has some drawbacks particularly when it is located on the vessel's quarter. Since the 1970s, most accommodation ladders are installed in way of the accommodation on the vessel's quarter and generally lead forward. This means that the pilot boat cannot rest parallel to the vessel's side during the transfer. This makes it difficult to keep the pilot boat's transfer deck in position below the bottom platform of the accommodation ladder. It is more dangerous for the pilot to climb onto or off the bottom platform when it is away from the vessel's side and swinging during the transfer. A pilot ladder meeting Canadian and international standards is usually deployed vertically on the parallel part of the vessel's side where the pilot boat can come alongside in a safe and stable manner. However, there are some drawbacks to using a rope pilot ladder. It is steep to climb and requires greater physical effort from the pilots, especially when the freeboard is high. The physical condition of some pilots and/or the fact that they may be wearing cumbersome clothing in winter are factors that can hamper a pilot using a pilot ladder. Finally, when the embarkation facility consists of a combination accommodation-type ladder and pilot ladder, pilots must transfer their weight from one ladder to the other. Sometimes the bottom platform of the accommodation ladder is not properly supported, which may also compromise the safety of the pilot. Although the NAVIOS MINERVA was equipped with a pilot ladder facility amidships, the crew did not deploy it because the MCTS centre at Les Escoumins had instructed them to prepare the accommodation ladder. In this instance, it would probably have been safer to use the combination of ladders for the pilot transfer. 2.3 Regulatory Requirements for Construction and Stability The functions of Transport Canada include, but are not limited to the review and approval of construction plans, stability data, and the subsequent inspection of proposed or existing vessels, to ensure compliance with applicable regulatory requirements. Such approval is based on the suitability of the submitted design parameters. The accuracy of the data presented is the responsibility of the owner and/or his naval architect. Consequently, regulatory approval is not specifically related to the operational efficiency or performance of the completed vessel. Compliance with established minimum regulatory stability criteria ensures that small vessels attain what are generally recognized as adequate intact traverse stability characteristics throughout a range of operational loading conditions related to their routine service. The regulatory criteria are such that the magnitude of the intact stability they provide generally ensures that the vessel also has adequate margins of reserve intact stability to withstand and recover from the dynamic effects of severe weather, or other detrimental external influences to be expected in normal operations. However, current criteria are primarily focused on transverse stability and do not address the longitudinal dynamic stability and trimming characteristics which may be of concern to small vessels that routinely operate at relatively high speeds in close proximity to larger vessels. 2.4 Operational Requirements The operational parameters of the NAVIMARV require that a relatively high hull speed be achieved to ensure short transit times between the pilot boat station and the transfer location with large vessels. The pilot transfer operation also requires that the pilot boat be capable of overtaking the vessel with ease, maintaining a steady speed and stable platform while alongside and pulling away from the vessel once the transfer is complete. These operational parameters largely dictate the hull form, weight and powering characteristics necessary for the vessel to be able to make the speed transition through the displacement and semi-displacement modes to top speed when a full-planing condition is achieved. The dynamic trimming characteristics applicable to all small vessels as they accelerate and make the transition from slow speed up to full planing speed are such that maximum wave making resistance and trim by the stern occur before sufficient hydrodynamic force has been developed to lift the hull into the full-planing condition. The length, hull form, displacement and powering of the NAVIMARV were such that the maximum after trim occurred at about 10 knots, which coincided with the speed through the water at the time of the occurrence. Consequently, at this speed, the pilot boat was in a highly vulnerable condition while maintaining station alongside and riding near the crest of one of the waves produced by the larger vessel. Any slight variation in the relative speeds of the two vessels would cause her to overtake the wave crest, surge down its face and bury her bow when she reached the trough. This sudden resistance to forward progress could cause the boat to slow down and plunge further into the sea as the wave pattern of the larger vessel continued at the original transfer speed of 10 knots. Although the trend is toward pilot transfers being carried out at higher speeds, a lower speed would reduce the height of the wave pattern generated by the larger vessels and would also markedly reduce the detrimental effects of excessive dynamic trim as the pilot boats would then be operating at a lower transition speed range. 2.5 Pilot Boat Design It is difficult to see how a pilot boat could be completely immune to capsizing or plunging, but pilot boat design criteria must meet the needs of the industry and pilotage authorities. By enacting regulatory standards that are better suited to pilotage operations, Transport Canada could minimize the potential risk of accidents in dangerous situations. Although Transport Canada has standards for pilot boats, the stability criteria in those standards do not comprehensively address the dynamic characteristics for small vessels such as the NAVIMARV. In its Devis pour la fourniture d'un service de transbordement de pilotes dans le port de Qubec[charter agreement], the LPA describes the minimum requirements for pilot boat construction. Article 5.10 states that all vessels must be equipped according to the Transport Canada Standards for Pilot Vessels, TP 10531, or must be capable of operating in a manner which is no less safe and efficient than if they were so equipped. This occurrence shows that the standards do not sufficiently address current pilot boat operational requirements. More recent pilot boats generally have a larger embarkation area forward of the wheel-house than aft of it, which makes it easier for the master to observe the transfer manoeuvre. Moreover, today's pilot boats operate at higher speeds during pilot transfers. Consequently, specific attention must be paid to their dynamic longitudinal trimming characteristics in the design stage, to ensure a safe operation throughout the vessel's displacement, transition, and full-planing modes. Aside from the TP 10531 standards, there are few reference documents for the design and operation of pilot boats in Canada. Transport Canada and LPA requirements for stability data and hull characteristics are minimal. After examining the proportions of a pilot boat, Transport Canada may waive the requirement for the owner to provide stability data. The design modification of the NAVIMARV seems to have been an exercise in trial and error. The series of modifications carried out in 1993, 1996, and in the spring of 1997, prior to this occurrence, were collectively unsuccessful in eliminating the perceived shortcomings in the vessel's dynamic trimming characteristics. Further modifications, after refloating the vessel in 1998, were made to reduce once again the detrimental after trimming characteristics. It is up to pilotage authorities which set operational and performance parameters for pilot boats to ensure that the vessels meet the needs for foreseeable operating conditions. With a broad counter stern, hard-chine hull, and relatively flat bottom, the NAVIMARV was likely to have sensitive dynamic trimming characteristics when operating at semi-planing speeds when in overtaking or following seas. In terms of general arrangement, the current trend in pilot boat design is for the steering station to be located in the middle of the transfer deck. There was nothing to suggest that the after deck of the NAVIMARV could not provide a stable and safe working platform for the pilots. However, the ergonomics of the NAVIMARV were not conducive to a full assessment of the situation, because the master had to divide his attention between the approach manoeuvre ahead and the transfer of the pilots behind him. In other words, he had to look forward to rest the bow on the vessel's side, to make sure it did not plunge into the sea, and also look aft to keep the after deck lined up under the accommodation ladder. TP 10531 does not address all these factors. 2.6 Manoeuvrability of the Pilot Boat The level of care and skill required of a crew manoeuvring a pilot boat are significant factors in this occurrence. Even the most experienced master may suffer a moment's inattention. An emergency manoeuvre to correct the vessel's behaviour may be as harmful as poor vessel design. The human factor is also part of the operating system. There is every indication that the crew were well rested and highly experienced; however, the relatively high speed at which the transfer was made and the waves generated by the NAVIOS MINERVA affected the pilot boat's dynamic behaviour when the NAVIMARV was in a vulnerable position against the vessel's side. The bulk carrier's speed was reduced to half ahead some three minutes before the pilot boat came alongside, but that was not sufficient time to take enough way off the vessel for the transfer. The pilot on duty overestimated the vessel's deceleration. Because the bulk carrier was moving at a speed through the water of about 10 knots, the waves she generated were probably unusually large. During the transfer, the pilot boat was manoeuvred onto the crest of one of those waves which was just forward of the accommodation ladder platform. Because the speed of the wave was less than the speed of the pilot boat, the NAVIMARV accelerated into the trough towards the next wave. Because the accommodation ladder was on the vessel's quarter, the bottom platform was not resting onto the vessel's side and the pilot boat's bow had to be rested on the vessel's side to line up the after deck under the accommodation ladder. When the pilot boat pitched forward on the wave crest, the boat surged down the wave's leading face, the fore deck became submerged, and caused the pilot boat to slow down in relation to the bulk carrier. The bottom platform of the accommodation ladder then caught up to the pilot boat and came in contact with the port side ventilation trunk. As the bow continued to plunge into the sea, it acted like a sea anchor, taking more way off the pilot boat. The momentum of the pilot boat caused it to continue its forward pitching motion until the vessel turned over. 3.0 Conclusions 3.1 Findings The Les Escoumins Marine Communications and Traffic Services (MCTS) centre instructed the NAVIOS MINERVA to prepare the starboard accommodation ladder to embark the pilot. Under international regulations, the vessel was required to use a pilot ladder to transfer pilots. Instructing MCTS traffic regulating officers to tell foreign crews to use the accommodation ladder is a request made by the pilots but is contrary to international regulations. The Canadian Pilot Ladder Regulations do not apply to foreign vessels. The vessel is equipped with a pilot embarkation/disembarkation facility amidships, but the crew prepared the accommodation ladder on the vessel's quarter. Because of the location of the accommodation ladder on the vessel's quarter, the ladder's bottom platform juts out more than a metre from the shell plating. The same accommodation ladder was used at the Qubec pilot station, and neither the pilots nor the master of the pilot boat objected to that practice. Most St. Lawrence River pilots use the accommodation ladder to board vessels. The pilot aboard the bulk carrier and the master of the pilot boat did not come to an agreement by radio communication on the time and position for the transfer. In Canada, there is no standard or code of practice for pilot transfer arrangements and pilotage duties. The ship NAVIOS MINERVA was making way at a speed through the water of about 10 knots at the time of the transfer. That speed is greater than usual. The pilot overestimated the vessel's deceleration. Because of the guardrails on the after deck of the pilot boat, she had to be moved farther away from the bulk carrier's side. The pilot boat was manoeuvred onto the crest of a wave generated by the bulk carrier. The speed of the waves generated by the vessel was less than the speed of the pilot boat. While trying to keep the after deck of the pilot boat lined up under the accommodation ladder and at the same time maintaining an angle with respect to the vessel, the pilot boat descended into the trough of the next wave and the bow plunged into the sea. The addition of concrete ballast did not completely eliminate shortcomings in the pilot boat's dynamic trimming characteristics. There is little reference material on pilot boat design and operation in Canada. Their development seems to result from operating experience and trial and error. The regulations prescribing the criteria for assessing pilot boat stability do not address the dynamic trimming characteristics of small vessels throughout the displacement, transitional and planing speed ranges encountered in normal operation. Transport Canada regulatory requirements and inspection criteria do not fully meet current pilot boat operational parameters. 3.2 Causes The pilot boat NAVIMARV overturned because when she came alongside the NAVIOS MINERVA, she overtook a wave generated by the ship, pitched onto the wave crest then surged down into the trough of the next wave before plunging into the sea. The submerged bow slowed down the pilot boat but, due to her momentum, she continued to pitch until the vessel turned over. The decision to use the accommodation ladder instead of the vessel's pilot ladder contributed to the sequence of events. 4.0 Safety Action 4.1 Action Taken 4.1.1 Safety Advisory In March 1998, Marine Safety Advisory (MSA No. 05/98) was sent to the Laurentian Pilotage Authority Canada (LPA) concerning the shortcomings noted in the pilot embarkation practice on the St. Lawrence River. 4.1.2 New Criteria for Awarding Contracts In preparation for renewing the contract for pilot boat services in the port of Qubec, the LPA revised its technical specifications and issued a call for tenders using stricter stability criteria for pilot boats. Bidders must now provide the plans of the proposed vessels. Besides speed criteria, the pilot boat must now meet the stability requirements of level STAB 6 of the Stability, Subdivision and Load Line Standards. 4.1.3 Technical Improvements to the Pilot Boat During the winter of 1997-1998, the owner of the NAVIMARV completely modified the pilot boat. A section of the vessel, from the bow to the forward bulkhead of the engine compartment, was removed and replaced by a new section. A new keel, one and a half times longer than the previous one, was added, making it possible to extend the forward part of the boat by 2.7 m. The new section contains two watertight compartments instead of one, and provides for greater forward buoyancy, that is additional upward thrust on the part of the boat that is forward of the longitudinal centre of gravity. Because of the larger forward deck, pilot transfers can be made forward. The forward deck and the after deck are both equipped with two guardrails in the centre to provide a handhold. The wheel-house and the passenger compartment were completely refitted. One of the two after doors was replaced with a wider window providing better horizontal visibility. The pilot boat is now powered by two Cummins turbo diesel engines developing 210 hp each. The twin-screw propulsion and power-assisted controls combined with larger rudders make for improved manoeuvrability. 4.1.4 Pilot Transfer Arrangement Discussion Further to a meeting held on 12 June 1998 between Transport Canada , the Corporation des pilotes du Saint-Laurent central, the Corporation des pilotes du Bas Saint-Laurent and the Laurentian Pilotage Authority Canada, Transport Canada issued a report and subsequently a letter indicating the following two recommendations: a) that transfer operations be cancelled where the accommodation ladder leads forward - unless a pilot ladder is used to climb the first 1.5 m; and b) that the master on board the pilot boat refuse to carry out the transfer operation if he deems the conditions for the transfer to be unsatisfactory. It was agreed that Transport Canada would issue a Ship Safety Bulletin if the parties came to a consensus, but such consensus was not reached. On 2 March 1999, the Corporation des pilotes du Bas Saint-Laurent indicated to MCTS, Quebec Region, that its pilots preferred the Canadian Pilot Ladder Regulations to international regulations and that it wanted them implemented even though they do not apply to foreign vessels.